Bluetooth Calipers Add-On

For mechanical designers, calipers are essential tools of the trade, allowing one to measure things with a precision far beyond a tape measure or ruler. Once measurements are taken, however, they often need to be input to your computer as CAD data. As seen here on GitHub, Mew463 no longer has to input these values by hand, but can instead send them to a computer wirelessly over Bluetooth.

The device bolts onto a standard set of calipers, and uses an ESP32-C3 to transfer readings. An onboard button inputs values, then presses enter on the computer, while a second button enters values, then inserts a space to enable the user to input a tolerance. It also features a NeoPixel indicator for pairing, button presses, and entering deep sleep.

The device has a 150mAh battery that allows for two hours of runtime between charges, and one might consider it a sort of wireless caliper/macro pad combo. It took around 40 hours of work and three PCB revisions to get correct, so if you just need a measurement tool, you might consider simply buying one. On the other hand, it was a fun project, and Mew463 certainly learned something in the process.

While inputting CAD data is one good usage for this type of system, quality checking operations might be even better. Imagine measuring part after part... after part, and comparing it to a good or bad value. With this type of caliper, you could instead use it to actuate a go/no-go lighting system, or even implement an automatic tracking setup for later reference.